Femtosecond laser synthesis of nitrogen-doped luminescent carbon dots from acetonitrile

Astafiev, Artyom A.; Shakhov, Alexander N.; Kritchenkov, Andreii S.; Khrustalev, Victor N.; Shepel, Denis; Надточенко, В. А.; Tskhovrebov, Alexander G.

doi:10.1016/j.dyepig.2021.109176

Cited by 22 publications

(17 citation statements)

References 47 publications

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“…The oxidation can also improve the surface defects of CDs, which generate more excited capture centers and present red-shifted fluorescence. 29,30 It was found that the extent of red shift was also consistent with the increase of the oxygen content and COOH groups on the surface of CDs. The CDs with excitation wavelength dependence have been successfully prepared with citric acid (CA) by thermal method.…”

Section: Introductionmentioning

confidence: 56%

Solvent Effects on Fluorescence Properties of Carbon Dots: Implications for Multicolor Imaging

Huo

Shen

et al. 2021

ACS Omega

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Carbon dots (CDs) are synthesized by the solvothermal method with four kinds of solvents including water, dimethylformamide (DMF), ethanol, and acetic acid (AA). The aqueous solutions of the above CDs emit multiple colors of blue (470 nm), green (500 nm), yellow (539 nm), and orange (595 nm). The structures, sizes, and chemical composition of the CDs are characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray diffraction (XRD), Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS). The optical properties of multicolored CDs are analyzed by UV−vis absorption and photoluminescence (PL) spectra. It has been revealed that DMF is the key solvent to synthesized CDs for the red shift of fluorescence emission, which could be enhanced by adding an AA solvent. The structures of functional groups such as the contents of graphitic N in carbon cores and oxygencontaining functional groups on the surface of CDs are affected by these four solvents. According to the oxidation and selective reduction of NaBH 4 , the implication for multicolor imaging has been discussed based on the COOH, C−O−C, and CO functional groups.

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Section: Introductionmentioning

confidence: 56%

Solvent Effects on Fluorescence Properties of Carbon Dots: Implications for Multicolor Imaging

Huo

Shen

et al. 2021

ACS Omega

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“…Recently we demonstrated that 2-pyridylselenenyl halides selectively react with a broad scope of nitriles to form adducts 3-14 in excellent yields (Scheme 1) [11,29]. Within this work, following our interest in CN and NN triple bond activation [30][31][32][33][34][35][36][37][38][39][40][41][42][43], we attempted to prepare analogous Te derivatives. 2-Pyridyltellurenyl bromide (16 was easily synthesized by the oxidation of di-(2-pyridyl)-ditelluride with molecula bromine.…”

Section: Resultsmentioning

confidence: 99%

2-Pyridylselenenyl versus 2-Pyridyltellurenyl Halides: Symmetrical Chalcogen Bonding in the Solid State and Reactivity towards Nitriles

et al. 2021

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The synthesis of 2-pyridyltellurenyl bromide via Br2 oxidative cleavage of the Te–Te bond of dipyridylditelluride is reported. Single-crystal X-ray diffraction analysis of 2-pyridyltellurenyl bromide demonstrated that the Te atom of 2-pyridyltellurenyl bromide was involved in four different noncovalent contacts: Te⋯Te interactions, two Te⋯Br ChB, and one Te⋯N ChB contact forming 3D supramolecular symmetrical framework. In contrast to 2-pyridylselenenyl halides, the Te congener does not react with nitriles furnishing cyclization products. 2-Pyridylselenenyl chloride was demonstrated to easily form the corresponding adduct with benzonitrile. The cyclization product was studied by the single-crystal X-ray diffraction analysis, which revealed that in contrast to earlier studied cationic 1,2,4-selenadiazoles, here we observed that the adduct with benzonitrile formed supramolecular dimers via Se⋯Se interactions in the solid state, which were never observed before for 1,2,4-selenadiazoles.

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“…Despite this, a great number of nanomaterials have been synthesized using lasers, including metal and semiconductor nanoparticles, along with CDs [26,65]. In particular, the latter have been obtained in both top-down and bottom-up approaches using various carbon sources (Table 3) [66][67][68][69][70]. The effect of laser fluence, wavelength, spot size, and irradiation time proved important in controlling the material properties (Figure 2).…”

Section: Laser Synthesismentioning

confidence: 99%

“…When fluence above 0.4 J was instead used, different size populations were formed, highlighting a detrimental effect on size distribution [75]. When acetonitrile was instead used as precursor, N-doped CDs were formed with high reproducibility, presenting broad absorption as well as dual excitation-dependent emission in the UV-blue region (λ em = 380 nm, 430 nm) [70]. The fact that laser radiation produced CDs starting from relatively unreactive solvents underlines how this approach can be used to extend the range of precursors in CD synthesis.…”

Section: Laser Synthesismentioning

confidence: 99%

New trends in nonconventional carbon dot synthesis

Bartolomei

Dosso

Prato

2021

Trends in Chemistry

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Carbon dots (CDs) are currently one of the hot topics in the nanomaterial world. Until recently, their preparation has been mostly based on solvothermal or hydrothermal syntheses requiring high temperatures, long reaction times, or toxic solvents. Moreover, the resulting materials are often affected by low reproducibility and difficult purification. A potential solution to these problems could be represented by innovative fields of chemistry, such as mechanochemistry, flow chemistry, and laser synthesis in the liquid phase. Machine learning could also be applied to go beyond the trial-and-error approach commonly used to explore the CD chemical space. In this review, we explore these recent approaches and their future potential to address some of the CD limitations, widening the range of properties and applications of these highly promising nanomaterials. Synthesis of carbon dots: current challengesCarbon dots (CDs) are currently one of the most studied carbon-based materials, due to their highly promising properties. CDs are carbon-based nanoparticles presenting dimensions <10 nm, emissions ranging over the whole visible spectrum, low toxicity, and long-term photo and colloidal stability [1,2]. Generally, CDs are synthesized following either a top-down or bottomup approach, with the latter more commonly used due to its superior versatility and accessibility [3]. In fact, CD synthesis mostly relies on hydrothermal or solvothermal treatment of relatively small molecular precursors (citric acid, amino acids, carbohydrates, anilines) involving either high temperatures/pressures, long reaction times, or toxic organic solvents [4][5][6][7][8][9][10][11]. This approach is highly appreciated for the simple and economic set up and for the wide range of precursors that can be employed. An improvement in solvothermal synthesis has been achieved by using microwaves. This resulted in a great reduction of reaction times and solvent amount, mainly arising from a more controllable thermal transport [4,12]. Despite these advantages, the high temperatures needed (>150°C) result in multiple reaction pathways that are not clearly predictable, leading to extensive formation of by-products, which are often highly emissive (Figure 1) [13][14][15][16][17]. As a result, various papers identified the presence of molecular fluorophores in CD samples, highlighting the urgent need for more stringent purification protocols [18][19][20][21]23,25]. This aspect, together with irregular heat and mass transfer typical of batch synthesis, often contributes to the low reproducibility observed in CD preparation [4,22]. Furthermore, the procedures used to tailor the obtained materials are still based on a trial-and-error strategy. This approach is limited by the absence of predictability, resulting in long and difficult optimizations of the target properties and extensive time consumption. To go beyond these limitations, approaches able to increase the reproducibility of the synthesis and finely tailor the material characteristics are required. A poss...

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Femtosecond laser synthesis of nitrogen-doped luminescent carbon dots from acetonitrile

Cited by 22 publications

References 47 publications

Solvent Effects on Fluorescence Properties of Carbon Dots: Implications for Multicolor Imaging

Solvent Effects on Fluorescence Properties of Carbon Dots: Implications for Multicolor Imaging

2-Pyridylselenenyl versus 2-Pyridyltellurenyl Halides: Symmetrical Chalcogen Bonding in the Solid State and Reactivity towards Nitriles

New trends in nonconventional carbon dot synthesis

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